singular and isoparameters;  fracture mechanics;  stress intensity factor;  Pavement

The stress strength factor of pavement crack tip is an important index to judge the crack propagation of crack. Using singular isoparameters and fracture mechanics theory, the single crack problem of pavement under three load simplification modes was numerically analyzed. The corresponding stress intensity factor of the crack tip was obtained by least squares regression near the crack tip, and the finite-width slats model was applied to perform numerical verification. The calculation results show that the fracture length and base modulus have a great influence on the stress strength factor of the crack tip, and the crack is easier to propagate under convex loading.